nyc4runnin
New member
So I know that the urd o2 sim needs the sensor in place for it to work correctly, but what if that sensor is completely dead, would it still throw the P0420 code ?
P0420 back again even with URD O2 sim !
- Thread starter nyc4runnin
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nyc4runnin
New member
bump ?
jsmarine
New member
No the front sensor should throw a different code; the front sensor is an Air/Fuel ratio sensor, the rear is O2. Check your wiring on the URD simulator.
EDIT: also check that the rear O2 sensor is still hooked up, the URD simulator still needs the O2 sensor to be there and hooked up for the simulator to work correctly.
EDIT: also check that the rear O2 sensor is still hooked up, the URD simulator still needs the O2 sensor to be there and hooked up for the simulator to work correctly.
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A printout of the p0420 code says that it is either the a/f sensor, exhaust leak, bad cat, or secondary 02 sensor failure so it could still be the one after the cat. Might as well replace one and see, then replace the other. You can check to see if they are good but I don't know how to do that.
nyc4runnin
New member
i know its for the rear sensor, and i still have it hooked up. but my question is what if that rear sensor is completely dead (like the ecu cant even see it) ? would it still throw a p0420 with the O2 sim installed ?
which brings me to another question .... what error code would you expect to get if the rear O2 sensor is not hooked up with the O2 sim installed ?
jsmarine
New member
I think the rear O2 sensor has to be working, not just hooked up; basically what the URD simulator does is intercept the signal from the rear O2 sensor and trick the ECU into thinking everything is OK. I bet you need to have a working rear O2 sensor in order for the URD simulator to work.
EDIT: I have the URD simulator by the way, and I had trouble with the P0420 code before I got the simulator,(Cali 4runner) but after putting in the URD simulator the code has not come back for me.
EDIT: I have the URD simulator by the way, and I had trouble with the P0420 code before I got the simulator,(Cali 4runner) but after putting in the URD simulator the code has not come back for me.
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nyc4runnin
New member
Would a completely dead rear O2 sensor throw a P0420 code ? or some other code ?
nyc4runnin
New member
Update: Changed the rear cat with an aftermarket bolt on one, changed both sensors with Bosch ones, removed o2 sim, CEL stayed off for 30 days ............and now getting a P0420 again .. but now i believe theres an exaust leak somewhere that I can hear. may have to go to the muffler shop to see if they can find/patch the leak.
jsmarine
New member
Yeah, get all the leaks fixed first and see if that keeps the light off.
Just an FYI, heres my story, but you probably dont want to hear this: I did the exact same thing, replaced both of my cats with aftermarket (Eastern) and both of my sensors with Bosch...and CEL light still came on (P0420). Then I replaced both sensors again, this time with Denso (OEM) and guess what...a few days later P0420 again! I gave up at that point until I learned about the URD simulator from here about a year ago. Since I installed teh URD simulator, no codes!
IMO aftermarket cats suck, and I even comfirmed this with Eastern on the phone, that my Cali runner will probably need OEM cats to keep the light off. Their cats (at the time, 2007) were not heavy duty enough to keep the light off on Cali 4runners. I dont know if yours is a Cali runner (check the sticker under the hood) but just thought I would give you my story.
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Doc2012
Senior Member
Is this suppose to say "f*cking bump since no answer?"
Sent from my PRC-119 using morse code
tx_shooter
New member
I thought I was still drunk from Friday; but apparently it isn't just me.
